Hydraulic pulsator system



April 1949-- H. K. PERRILL 2,466,908

HYDRAULI C PULSATOR SYSTEM Filed May 18, 1946 3 Sheets-Sheet 1 INVENTOR. fi/ar/an K PerH/l A TTOEA/EY Patented Apr. 12, 1949 UNITED STATES PATENT OFFICE 2,466,908 HYDRAULIC PULSA'I OR SYSTEM Harlan K.. Perrill, Qakland, Calif. Application May 18, 1946, Serial-No. 670,755

6 Claims.

This invention relates tohydraulic control SYST- tems and is concernedrnore particularly with the provision: of a hydraulic control throttle system for use in controlling the operation. of multiple power plants, for example, of the type employed in multi-engine airplanes, speed boats and locomotives.

It is ageneral object of the invention to. provide an improved throttle control system :of the above character which enables a flexible control of the power plantsunder varying conditions and requirements of the operation of such plants.

Another object of the invention is to provide-a throttle control system ofthe above character which enables automatic synchronizing of multiple control devices to maintain coordinated engine speeds in a multiple power plant, and optionally to enable individual independent operation of the units of thepower desired.

A. further object ofthe invention is. to provide a control system attainingthe foregoing objects and which enables: independent emergency: out! Off of any one. power plant when required;

Still another object of the invention is to provide a hydraulic control: system which: is simple and reliable in its. operation and which lends itself to theforegoingobjects.

Other objects of the invention-will be apparent from the following description of. av preferred embodiment thereof asillustrated in. the accompanying drawings, in. which: Figurev 11 is a schematic: elevational. view of: a throttle control systemincluding a, master hydraulic control: unit. connected for controlling the operation of arfour-unit powerrplant in. conjunction with four individual. hydraulic control units associated with the. respective units of the power plant.

Figure 2 is a schematic view. of. a control; system of, the. type: employedin: conjunction with spring-urged elements, suchas. governor elements, for-example.

Figure 3 is a, sectional viewthrough themaster hydraulic, unit of" thecon-trol system, the view being. taken as indicated by the line, 3-:-3. in Figured.

Figure4 is a sectional view through; a portion of the master hydraulic unit taken as indicated by..the line.4-li.in Figure 3...

. Figure 5 is a horizontal. sectional view ofthe unittakenlin planes indicated by. the: line. 5-5 in Figure 3.

Figure. 6.1519, sectional. eleyational view. of. an

individualhydraulic unit.

plant when speeds (c1, (id-54.5)

' ample-in multi-engineairplanes, it is necessary that the pilot be provided with.a-.flexible control system of the throttles of. thev various; engines of; the power plant which will enable easy, fast operation. to control the speeds of the various engines for maneuvering and which will relieve the pilot of the; necessity; for synchronizing-the where it; is desired to maintain constant speed; operation of: all. of. the engines. In ac:- cordancewith the instantinvention, the desirable features of simultaneous or'individual control. of engine speed, propeller speed or; the" like is provided by; means. of a hydraulic controlsystem embodying a, master control unit which can be placed in control of; the entire. system and a plurality of. individual control unitswhich can be; operated for individual. control withthe mas.- ter control unitdisabled or ineffective.

.For example, referring to Figure 1; there is illustrated schematically a: suitable form of hydraulic. control system including a master unit I 0 having an operating handle. H associated therewith and a. plurality of individual control units l2' havingv respective: operating handles I3 associated therewith. In. this .case thereare pro;- vided four throttle control shafts l4, each of whichcanbeoperated through a lever l5 from the respective. plungers l6, and ll of operating cylinders l8. and. I9. Thecylinder. 18. may be designated, an increase cylinder while l9v is a decrease cylinder; The respective cylinders t8 and- |9.- are connected through respective con:- duits 2m and 22a to one. of the individual con trol. units t2, and by branch conduits 2land 22 leading from the individual control unit l2'to the master control unit. lfl. In. this, type of installation, boththe master control unit In and each of the individual controlunits H are provided with increase and decrease cylinder and plunger units so that positive. operationof the plungers l5 and I] may be provided in both directions.

In the form otcontrol systems shown: in Figure 2,,the master control unit Ito and the individual control unit lza operateagainst the pressure of a. spring ztinassociation with .the'governor ele- 'secured thereon by 'ments 21, so that the plunger 23 Within the cylinder 29 is operated by the hydraulic fluid in one direction and by the spring 26 in the other direction. In this case only one cylinder-plunger unit is necessary in the respective control units.

The master control unit is illustrated in detail in Figures 3 to 5, inclusive, and includes a body 3! in which respective increase and decrease cylinders 32 and 33 are machined. Respective plungers 34 and 36 are provided Within the cylinders 32 and 33 with operating shafts 3'1 and 38 extending outwardly through one end Wall of the cylinder 32 and through a closure 39 for the cylinder 33. Respective packing glands 4i and compression caps 42 are provided about each of shafts 37 and 38. The respective shafts 31 and 38 are connected lower end 44 of the operating handle H which is pivotally mounted on a cross shaft 46 supported on a bracket 41 and a shaft retaining cap 48 cap screws 49. The cap 48 is provided with an arcuate locking strap 53 having a notch i cooperating with a spring-urged lock 52 which is slidably mounted on the handle H and has a release handle 53 disposed below the handle portion 54 of the handle structure i I. As

shown, the plungers 34- and 36 are locked'in in operative position by the handle structure.

In accordance with the instant invention,

means is provided for by-passing liquid between respective portions of the cylinder at either side of the plunger or piston and the plungers 34 and 36 are of the apertured type to pass the hydraulic fluid freely from one side to the other of the plungers. In this case the plungers are provided with four apertures 56 which extend to the ground conical upper face 5'! of the plunger 34 and similar lower face 58 of the plunger 36. These conical faces 5! and 58 mate with and seat against similar ground conical end surfaces of the cylinders 32 and 33 to provide'a seal. If desired, a rubber gasket could be employed between these sealing surfaces.

The end'wall of the cylinder 32 (Figures 3 and 4) is provided with four drilled outlet passages 61 which extend from the conical end of the cylinder 32 to the four connecting nipples 62 which, as previously described, are connected by the respective conduitsZ'l to the respective increase cylinders ill of the throttle operating linkages. The conical end Wall of the cylinder 33 is similarly provided with four drilled passages 63 which are connected to connecting nipples 64 which, as previously described, areconnected by the conduits 22 to the decrease cylinders I 9 of the throttle control linkages. As clearly seen in Figure 3, the drilled passages 56 of the plungers 34 are oifset with respect to the drilled passages 6!, so that in the seating position of theplunger 34 thesepassages are disconnected. Similarly, the drilled passages 56' of the plunger 36 areoffset from the drilled passages 63 in the decrease cylin der so that these passages are similarly closed in the seating position of the plunger 3t.

It is well recognized that there is a certain degree of elasticity or compressibility in the liquids used in such systems. The slight degree of elasticity or compressibility of the liquid within the cylinders 32 and 33 will permit a very slight initial movement of the pistons 34 and 36. This movement, even though slight, is sufficient to permit the passage of liquid through orifices 56 and also to permit the conical faces 51' and 58 to be separated slightly from the corresponding surfaces of cylinders 32 and 33. In this manner, initial by links 43 tothe bell crank movement of the pistons will take place and the flow of oil or other hydraulic fluid through the orifices 56 and 6| will take place.

From the above description it will be apparent that upon movement of the control handle II counter-clockwise from the position shown in Figure 3, the respective plungers 34 and 36 will move within their cylinders 32 and 33 opening the passageways El and 63 and causing a flow of hydraulic fluid through the respective plunger passages 56 from one side of each plunger to the other. It will also be apparent that the effective volume of each of the cylinders 32 and 33 is changed by the volume of the shaft 3'! or 38, respectively, which is disposed within the respective cylinderw Thus, in Figure 3, the cylinder 32 contains its maximum volume of hydraulic fluid, while the cylinder 33 contains its minimum volume, so-that movement of the handle H will result in displacement of fluid from the cylinder 32 and intake'of 'fluid'into-"the :cylinder 33. 'will'b'e later :pointed 'out, this amount oft-fluid is in definite volumetriorelation to fluid displacement within the individual control units which will now be described. 1 r T As each of the individual control units is of identical construction, only one will'be described in detail. Referringto Figures 6 to 8, each'individual control unit I 2 includes a body having similar increase and decrease cylinders 12 and 73 drilled therein. Respective increaseand decrease plungers 14":and16are'disposed within the respective cylinders andare connected ,by links I? with thew-operating" handle l3. The handle I3 is of the same general structure and mounting as the operating handle 1! of the master unit. Respective sealing gaskets 78 and clamping caps 19 are associated with each of the plungers 7'4 and -16. 1

Each of the plungers 74 and 76 (Figures 6' to 8) is provided ,witha conical lower end 8| adapted to engage a conical" seat'at the lower end-of the associated cylinder from which a drilled passageway 82 extends; v. The lower portion of-this passageway 82"1eads to a :fitting by'means' of which the individual cylinders 'may' be connected to the associated operating cylinders. Efach passageway 82 is provided with a branch 84 leading to an L-shaped passage 86 in a cylindrical cut-01f valve 81 disposed within acylindrical bore of an extension "Id of the body. The valve 81 has an operating handle 88 disposed exteriorly of the bodyadjacent acasing 83 which houses the closure caps 91 of the respective cut-off Valves described above. Adjacent eachsection of the shaft 81 provided 'with the L-shaped passage -86, the shaft 81 is grooved to receive a sealing gasket 92. One of the L-shaped passages 86 is adapted to register with an increase nipple 93 a'ndthe other with a derea'se" nipple 94 which, as previ ously-described, are connected by the respective branch conduits 2| and 22 to "the increase and decrease cylinders of the master control unit.

As shown in Figures '6 to 8, the cut-off valve is positioned 'to place the cylinders 12 and 13 in operative relation with respect to thissystem. However, if the operating handle 88 of a particu lar cut-01f valve is moved' clockwise, as viewed in Figure 1, then the" passageways 84 are blocked and the particular individual throttleis disconnected from-thejmaster cylinder and the master cylinder is ineffective with respect'to this in dividual control,

From the above description it will be seen that, assuming the master throttle i'sinactive, the mob To provide for uniform actuation of the increaseand decrease actuating cylinders I8 and -l9ieither-by the. master throttle unit or th ir individual: throttle units. the s aft p rtion o t master throttle plunsersqhave such diameter and :lensthoi. stroke that the vol m in e or deere sexwithinthe respect ve mast yl nders: is equal to the combined olum s of all of the o responding individual plungers. Thus, as the master increase plunger. for example, moves down, as viewed in Figure 3, the volume available for fluid is decreased by the volume of the shaft 31 which enters the cylinder 32, and fluid is displaced from the cylinder 32 and is forced through the conduits 2i and Zla into the increase cylinder l8 which operates the plunger of the decrease cylinder l9 which correspondingly transmits fluids back through the lines 22 and 22a to the master decrease cylinder 33. If the individual throttles are locked in closed position, as shown in Figure 6, the connection through the conduits Zla and 22a is ineffective to produce any change in the adjustment of the single throttle plungers 14 and 16.

If during operation one of the engines gets out of synchronization, the tendency to become synchronized Will exert a force on the piston 28 (Figure 2) of this control unit which will (through the interconnection of the various lines 2| and 22 to the master throttle chambers 32 and 33) produce or tend to produce a corresponding change in all of the other governor units. Thus, any individual condition in connection with an individual engine of a power plant when the master throttle control is active will be automatically compensated for and at all times the interconnected hydraulic system insures a similar position of all of the governor pistons 28.

On the other hand, when it is desired for some operating reason to provide for different engine speeds, the individual throttle handles are unlocked and moved as a gang and at the same time the master throttle is restored to locked condition. In this way the fluid displaced from or taken in by the master control cylinder is balanced by the displacement of the various individual increase and decrease plungers I l and 16. After the above adjustment, each individual plunger is in control of its associated throttle control shaft and the desired individual adjustment of the various engine speeds can be effected.

In case of any emergency, such as damage to an individual engine, the individual engine can be cut ofi from the control system by operating the emergency cut-off valve 81 so that the individual throttle control and the associated operating cylinders l8 and H] are isolated from the remaining portions of the system which remain under control of the master throttle unit. In performing this operating the single throttle control unit corresponding to the damaged engine is first unlocked and advanced to a position substantially equal to that of the master throttle control unit after which the cut-off valve is closed. In this condition of the parts the individual throttle control unit can then be operated to shut down the engine or to operate it after adjustment or repairs when these can be made.

. While-11 h v showna-nreier ed embodiment; of the invention it will be; understood that theing- .ti n is ca ble oi var a i nd modificat from the-"form," shownsothat its scope shouldb e limited only b ithe scope of the cla ms-appended hereto. Y

. I c aim:

, i. In a hydraulicthrottle control system for-a plurality of hydraulically es n t ontrolelements, a imaster transmitter unit including gmaste iwli der having inlet and outlet passages and an apertured plunger therein having an operatingshaft egrtendingthrough an end wall of the cylinder, a plurality of individual receiver units each including a cylinder and a plunger therein, said master and individual cylinders being connected in parallel to said throttle control elements, said apertured master plunger having a position blocking the inlet and outlet passages from said master cylinder.

2. In a hydraulic throttle control system for a plurality of hydraulically responsive control elements, a master transmitter unit including a cylinder having a conical end Wall and an apertured plunger disposed in said cylinder and having an operating shaft extending through said end Wall, said plunger having a conical face to engage said conical end wall, a plurality of individual receiver units each including a cylinder and a plunger therein, said master and individual cylinder being connected in parallel to said throttle control elements, outlet and inlet passages to said master cylinder leading from said end wall, said apertured master plunger blocking said inlet and outlet passages when engaged with said end wall.

3. In a hydraulic throttle control system, a master transmitter including a cylinder and an apertured plunger therein having an operating shaft extending through an end closure of the cylinder, a plurality of individual receivers each including a cylinder and a plunger therein, and conduits leading from said master cylinder end closure to said individual receiver cylinders, said master plunger having an end position adjacent said end closure closing said master cylinder from said individual cylinders.

4. In a hydraulic throttle control system for a plurality of hydraulically responsive control elements, a master transmitter unit including a cylinder and an apertured plunger therein having an operating shaft extending through an end closure of the cylinder, a plurality of individual receivers each including a cylinder and a plunger therein, and conduits leading from said master cylinder end closure through said individual receiver cylinders and to said control elements, and a cutoff valve between each individual cylinder and the conduits leading thereto from the master transmitter control unit.

5. In a hydraulic throttle control system for a plurality of hydraulically responsive throttle control elements, a master transmitter unit including a cylinder having a plunger therein, a plurality of individual receiver units each including a cylinder and a plunger therein, said master and individual cylinders being connected to said throttle control elements, and a cut-off valve between each of the individual receiver units and the master unit and disposed to block control of the master throttle unit over one of the throttle control elements while leaving the associated individual receiver unit effective with respect to the throttle control element.

6. In a hydraulic throttle control system for a plurality of hydraulically responsive throttle con- "trol elements, a master transmiter unit including aifidoos 7 REFERENCES CITED a cylinder having a plunger therein, a plurality -'The following references are of record in the of individual receiver units each including a cylfile of this'patent:

"inder and a plunger'therein, said master and individual cylinders being connected to said throttle 5 UNITED STATES PATENTS control elements, andselectively operable means Number I Name te for blocking control or the mastertransmitter 1 1 Rasmussen D 5, 1939 junit over one of the throttle control elements 34,008 rice Mar. 4, 1941 While leaving the associated individual receiver 10 2,243,385 Levy May 2'7, 1941 *unit effective with respect to the throttle control 2,299,912 Loweke Oct. 27, 1942 f'element. 2,356,517 Hale Aug. 22, 1944 HARLAN K. PERRILL. 2,414,302 Hebel Jan. 14, 1947 

